Joint for lock-bar pipes.



-No. 761,067. PLATENTED MAY 1, 1904.

T. A. GILLESPIE.

JOINTFOR LOOK BAR PIPES.

APPLIOATION Hum AUG. 7, 1902. NOMODEL.

2 sums-sum 1.

No. 761,067. PATENTED MAY 31, 1904. I

-T. A. GILLESPI-E. JOINT FOR LOCK BAR PIPES.

APPLICATION FILED AUG. 7, 1902.

N0 MODEL. 2 SHEETS-QHEET 2 UNITED STATES Patented May 31, 1904.

PATENT OFFICE.-

THOMAS A. GILLESPIE, or WEST ORANGE, NEW JERSEY. I

JOINT FOR LOCK-BAR PIPES.

SPECIFICATION forming part of Letters Patent No. 761,067, dated May 31, 1904.

Application filed August 7, 1902.

. ing drawings, forming part of the same.

Lock-bar pipes are composed of two or more longitudinal plates of iron or steel hav-: ing their edges upset to form a laterally-expanded rim, usually of dovetail shape in crosssection, connected together by longitudinal bars having grooves in their opposite sides, in which the upset edges are secured by compression, so as to form a tight union of the several parts. The lock-bars are relatively thicker than the plates, and their sides project along the inner and outer sides of the completed pipe.

The advantages of lock-bar over ordinary riveted pipe consist in the avoidance of riveted longitudinal seams between the edges of the plates, which weaken the pipe, and in the fact that they can be made in long sections, the usual length of a section being about thirty feet, while an ordinary riveted pipe-section is made up of several plates which vary in length from four to eight feet, according to the diameter of the pipe, and the lessening of friction by the great reduction of the number of transverse joints and the substitution of smooth lock-bars for thelines of longitudinal rivets. A serious objection, however, to the use of lock-bar pipes is the expense and difficulty of connecting the sections to each other, and it has been customary to do this by means of metal sleeves having a calking groove or recess at each end which requires to be calked with lead or other suitable material, lead, however, being commonly used. These sleeves are made with folds or bends which extend over the externally-projecting lock-bars and add to the expense and difiiculty of making and calking the sleeves. The pipes are large, usually running from thirty inches in diameter up to much larger sizes, and the sleeves not only require a large amount of metal to make them, but=have to be made with great care,

Serial No. 118,700. Hi0 model.)

designed to obviate these difiiculties and to afford a cheaper, simpler, and stronger oint between the pipe-sections. I

To enable others skilled in the art to make and use my invention, I Will now describe it by reference to the accompanying drawings, in which Figure 1 is a longitudinal view, partly in section, of my improved lock-bar pipe-joint. Figs. 2, 3, and 4 are cross-sections on the lines a :0, y y, and z z of Fig. 1. Figs. 5 and 6 show another way of making my improved joint. Fig. 7 is a view of several sections of pipe united with my improved joint.

Each section of pipe is composed of two or more longitudinal plates a, the edges of which are upset into an approximately dovetail shape a; The plates are joined together by lock-bars 6, having grouped edges which receive the dovetails a of the plates. The overlapping edges of the lock-bars are pinched or upset around the dovetails a of the plates. In ordinary lock-bar pipe the thick lock-bars extend to the ends of the pipe-sections; but in making my improved joint I turn down or plane off the outer side of the ends of the lock-bars, as shown at 0, so that the outside of the pipe shall be a perfect circle, as illustrated in Fig. 2, a sufficient distance back from the end to permit of the use of a screwcoupling sleeve 03. The ends of the pipes are then screw-threaded, as shown at e, and are thus adapted to be united together by cylindrical coupling-sleeves, as shown in Fig. 1.

In Figs. 5 and 6 I show another way of preparing the pipe-sections for use with threaded coupling-sleeves. Here the pipe-sections are made with lock-bars which are shorter than the plates a a suflicient amount to leave room at the ends for the application of the coupwhile the operation of calking them requires ling-threads. This leaves an open space of rectangular shape between the plates at the ends of the section, as shown at f, on opposite sides of the pipe. This space I fill by Welding in a suitably-shaped piece of metal g, forming the outside of the end of the pipe into a circle, so that it may be threaded for use with the threaded coupling-sleeve (Z;

By my improvement I am enabled to avoid the use of the costly and troublesome sleeve and lead calking heretofore used, avoiding the danger of leaky joints due to their inability to resist the effect of expansion and contraction, and in lieu thereof obtain in my improvement a simpler, cheaper, and stronger joint. I am enabled to overcome the most serious'difliculty experienced in theuse of lock-bar pipenamely, the difficulty and expense of properly uniting thesections. The extension of the-'lock-bars into the ends of the other sections, as shown in Fig. 1, strengthens the joint and stifiens the pipe-line.

If desired, the couplings d may be Welded to one end of the pipe-sections, with their 2.5 projecting ends internally threaded to receive the smaller or externally-threaded ends of other sections, as will be understood. This I regard as an equivalent Way of forming the joint. In any case the external ends of the lock-bars terminate back of the ends of the sections a sufiicient distance to permit of the attachment of the coupling at the peripheral line of the pipe Whether said lock-bars are planed off externally or are made shorter than the plates used in forming the pipe-section.

What I claim as my invention is .l. Alock-bar pipe-line, in Whichthe lockbars terminate externally back of'the ends of the sections, and the sections are connected together by threaded couplings arranged between the external ends of the lock-bars; substantially as and for the purposes described.

2. A lock-bar pipe-joint, in which the external ends of the lock-bars are reduced tothe periphery of the pipe, and the pipe-sections are externally threaded at the reduced parts and are connected together by threaded coupling-sleeves; substantially as and for the purposes described.

THOMAS A. GILLESPIE.

Witnesses:

THos. D. HARRIS, Z. ROSENFIELD.- 

